Automatic telephone system



Dec. 18, 1928.

F, ALDENDORFF AUTOMATIC TELEPHONE SYSTEM 3 Sheets-Sheet 1 Original FiledFeb. 14. 1922 IQTJ 000 7 m II. N; m4 H -Q VL mm w WKIIW 7?! i v Dec. 18,1928.

F. ALDENDORFF AUTOMATIC TELEPHONE SYSTEM Original Filed Feb. 14. 1922 3Sheets-Sheet "mu 8 w a o O 5/ Q 2 7. 9 0 w 1 3 3 in: 5 W u 8 m 3 w W M,/l 6 7 nuw H? a w nw h/bb 5 f a w tutu w wrlTl 61 u y g. +A|% lmlllfi vu 2 w W x 5 J W I 6 1 J m 1 3 6 6 h W a 55 J Illa/ an on- FAZdendoPatented Dec. 18, 1928.

UNITED s r-Ares PATEN PU F-ICE.-

FRI'JZZ ALDENDORFF, or 13Ea1,IN --.'virrL1i[Ens]:o RF, GEEMANY,nssrenonor ,ONE-FOURTH TO PAUL KOLISCH, on NEW x031 N. Y.; CHARLOTTEALDENDORFF soLn HVEIR 0F SAID B Z EN'D i I DECEASED- ai 'roivrarrcTELEPHONE sysrnm.

Original application filed February M, 1922, Serial No 536,504, newPatent No. 1,641,145, dated September 7 6, 1927, and in Great BritainMay 17, 1921. Divided. and this application filed April 7,1926. Serialno. 00,291 I This invention" relates in general to -telephone systems inwhich the connections between the subscribers lines are set up with theaid of electromechanically controlled switching apparatus and isadivision of application Serial No. 53655041 (United States Patent#1,6417,145). One oi the chief objects of the invention is to simplifythe mechanical construction' of the switching devices. To this end thesystem is' arranged in such a manner that the switches employed forestablishing talking connections areuni-lnotional that is each haswipers that only execute simple rotary motions or, if preferred,straight line motions. bi-motional switches may be entirely dispensedwith, without 'perceptibly slowing down the speed with which theconnections are obtained. Another feature of the invention is that aca'lling party selects the desired number, but not actually the desiredline, by means of devices which revert to common use as soon as atalking connection is set up between the lineof the calling party andthe desired lineby talking connection switches. The selectingimpulsesforselecting a desired number are partly sent into, a device permanentlyassociated with. a talking connection switch and partly into a wantedline designating device which may be common to a numberoftalkingconnedtion switches. i

Another feature of the invention is the use i of a switch or switcheswith a singlewipen driving means, a primary numerical device forselectingany desired group oi bank con tacts in the'swi-tch,and-asec'ondarry numerical device for controlling the driving mechanismwhilst the wipers are being set onto a'certain contact (or set ofcontacts) in'the selected group of bank contacts. Circuit arrange mentsare provided for enabling one orinore secondary devices to be used forcontrolling the driving mechanism of any one of a number of talkingconnection switches. A connecting device is provided forconnecting asecondary controlling device to any talking connection 7 switch. Aconnecting device which is arranged to connect an associated switchcontrolling device to another talking connection trunk as soon. as theprevious In accordance with this invention,

with this latter finder.

of bank contacts of the talkingconnection switch. v

The connecting devices ortrunk finders are so arranged that the releasefrom a trunk depends 'fiIStly on the calling subscriber being connectedto said talkingtrunk and secondly on this trunk being connected toanother trunk or tea line leading to a desired subscriber. The releaseof the trunk finder is eflected by acircu-it (controlled :by the releaserelay of the transitorily engaged finder and by a relay associated withthe 'trunkfinder that is de-energized at the moment whena talkingconnection is extended through the talking connection calling-linefinder to the wipers of the switclrassociatcd The connection of thecalling subscriber is transferred from a transitoi'illyusecl trunk totheitalking trunk at v a certain moment. Up to the moment when theconnection of the calling subscriber to' the talking trunk, the releaseof the line selecting or designating switch is under the is transferredfrom thetransitorily ised trunk H control ofthe release relay associatedwvith the transitorily used trunk. At the moment when the'connection.of-the calling subscriber is transferred from the transitorily nsedtrunkto the talking trunk,"the release of the line selecting switch is madedependent on a device associated with the vtalking connection callingline l'lIlCl1-. Atthemoment when the connection of thecalling'subscri'ber is extended through a talklng connection callingllne finder and its associated trunk to another trunk or line) the 'lineselectingswitch is released. The line selecting or designatswitchisreleasedat any moment during the progress ofthe connection through thetr-ansitorily engaged switchesby the de-energizatiou .ot 'theirassociated release relay,

- DS identifies calling lines in the banks of or, during the progress ofthe talking connection through the talking connection calling linefinder, by the deenergization of a relay associated with this finder.Means are thus provided for properly releasing, at any moment in whichthe call may be abandoned, all the devices allected in making a call ina system using by-paths for selecting purposes. Further features of theinvention will appear hereinafter and in the claims and drawing in whichlatter Figs. 1 and 2 show the circuits and switches of a complete systememploying transitorily engaged marking switches for designating thegroup and terminal 10- cations of wanted lines in a main lineswitch.These figures also show atransitorily engaged. line linderand apreselecting trunk finder switch and Fig. 8 shows amodificacation of theauxiliary arrangements for set ting a talking connection switch or mainswitch onto a wanted line or trunk.

Referring to the drawings 8 represents a calling subscriber, CS is atalking connection calling line finder, WS is a talking connectionwanted line finder, T is a talking connection trunk "forming a linkbetween the finder CS and the numerical switch VVS, T-F

is a trunk finder," F is a transitorily engaged,

finder, S is a units selector or wanted line designating switch.- When asubscriber S makes a call his line is first connected by a finder F to aswitch Sand his selecting impulses pass through the finder F partlythrough the associated trunk finder TF into a group selecting device Sgand partly into the units or line selecting device S. The impulses sentinto the group selecting device 89 immediately cause the wipers of thefinder VVS to start travelling towards the selected group or bankcontacts. and when they have reached this group they continue travellinguntil they reach a contact designated by the units selector P. W' hentheyhave reached this contact the selected line is tested by a testrelay 27/ associated with thefindcr WS.

If the tested line is tree the test relay ener gizes. 7 Meanwhile thecalling line finder CS will have moved its wlpers onto the bank con-'tacts corresponding to the line of the calling subscriber S. hen theline finder CS has set its wipers onto the calling line and, in additionto this, the test relay tr responds, the line of the calling subscriberS is switched through to the wanted line and the trunk finder TF iscaused to set its brushes onto another trunk T which is neither engagedby a conversation nor seized by another trunk finder. The by-pat-hconsisting otF, TF and S may then be used for another connection. a

An identifying switch DS isprovided for a group of finders F. Thisidentifying switch the switches CS and F in such a way that a callingline finder US will never connect to any calling line except the one bywhose call it is affected. I 7

Another identifying switch DS is provided for a group of units selectorsS. The identifying switch DS prevents a called line finder TVS fromstopping on any wanted line excepting the line selected by the callingsubscriber and connected to the finder VVS. The release of the unitsselector S depends on the release relay 1" up to the moment when thecalling subsoribers line is found by the line finder CS. At'that momentthe releaseof the switch S is made to depend on arelay 3 associated withthe finderCS or on the test relay tr.

The operations involved in establishing a talking connection will now bemore fully described. w'When the calling subscriber Elraises hisreceiver the line relay 4. associated. with his line is energized by acurrent which flows from the positive pole throughl, contact 5 ofcut-ofit' relay 6, limb b of calling line,

instrument S, limb c ot a calling line, contact? of cut-otl relay, otherwinding 0t line relay 4 to the negative pole, The line relay 4 on.energiz ng prepares astoppmg circuit by means of its contact 9, closesan operating circuit of a transitonly used finder F at its contact 11,and renders the calling line busy ping relay 24;, brush 28, stoppingwire 31, contact 9, cut-oil relay 6 to the positive pole. The relays 6and 24 are thus energized, the

latter relay opening the circuit of the operating magnet 25 at 13,preparing an identifying circuit at its contact 14;, preparing a circuitat 15 which extends through the relay 33 and the contact 32 when therelay r is energized, reducing the potential on the stop ping wire 31by. closing its contact 16 and extending the subscribers line a, Z) tothe impulse relay 85 through its contacted? and 18. The cut-off relay 6disconnects the line relay from the subscribefis line at its con tacts 5and 7 and connects itself to the stopping wire through its contact 8thus making its circuit independent of the contact 9 of the line relaywhich is opened as soon as this relay is cut oltfrom the calling line asde scribed.

, The calling subscriber, over whose line cur rent now flows through thewindings of the impulse relay 35which in turn has energized the releaserelay 1" by a circuit extending from the positivepolethrough 21,1", 36,to the negative pole, now commences sending his dialling impulses. Thecontacts 32, 38, 39, 10,42 of the release relay rare closed and thecontacts 34:

and 11 of this relay are now open. At the contact 10 a circuit is closedwhich extends from the negative pole through 40,-relayi3, wiper 415 oftrunk finder TF, corresponding bank contact, wire 50, relay 51,-conta'ct52 to the positive pole] This circuit helps to control the release ofthe secondary or units designating switch S and of the primaryor tensdesignating switch S9 as Wlll hereinafter more fully appear.

WVhen the calling subscriber sends in his dialling impulses intermittentclosures ofthe" contact 22 will take place due to the deenergization ofthe impulse relay 35 and tens impulses will flow from the positive polethrough 22, contact 39, Wire 53, off-normal contact 5 1, slow-actingrelay 55,wire 56,

wiper 46, corresponding bank contact of trunk finder TF, wire 57, wire58, operating magnet S9 of the tens designating switch which has aswitch-arm 59 and an arcuate member60 adapted for connecting thenegativepole to any number of contacts 61, 62, 63

' at one and thesametime. According to the number of-tens-impulses sentthrough the operatingmagnet Sg fewer or more contacts 61,62,63 Wlll beconnected to the negative pole by the member 60. If only one tens im- Itwill be assumed that-the calling subscriber has sent in three tensdialling impulses and that the member 60 has therefore appliedthenegative pole to the contacts 61,62 and hence to the contacts65, 66. Assoon as the negative pole is applied to the contact 61 an energizingcircuit for the operating magnet '68 of the main switch VVS is closedwhich extends from the negative pole through 61, 65, wiper 69 of thetalking connection switch VVS, operating magnet 68,-interrupter 2' tothe positive pole. The wipers will now be'driven forward by the magnet68 until the wiper 69 is driven off the \Vhen the release relay 7'closes its con' tacts 38 itthereby establishes an energizing circuit forthe operating magnet 74 of the calling line identifier. DS. This circuitextends from the negative pole through 38, 75, operating magnet 7 41 tothe positive pole. The

magnet 74 drives the wipers 76, 77, 78 of the identifier DS forwarduntil the wiper 77 reaches the'contact 80-to which thenegative pole hasbeen applied by thecontact 1 2 ofthe releaserelay'r usedfor theparticular connection. A currentthenflows from the positive pole throughthe relay 7 9, wiper 77,- bank contact 80, contact 81 of relay 82,contact 42 to the negative pole. Therelay 79 opens the-operating'circuitat contact 82 so that the wipers 76, 77, -78'stop onthe bank contacts 83, 80, 84 leading to the particular finderF and trunkfinder TF appropriated for the call in question.

W'Vhen the relay 1 was energized and thus caused the energization of therelay 51 as previously described, it also started the operation of-thevoice current cailing line :[inder CS by'means of a circuit thatextendsztrom the ne ative pole through contact 86, wire 87, bank contact88, wiper 89 wire 90, contact 91 of the identifying relay 92 operating1nagnet'93 of the voice current finder CS, interrupter r to the positivepole. 'W hen the wiper 89 is driven 011' the bank cont-act 88 onto thecontact strip at, the circuit of the operating niagnet 93 extends "fromthe negative pole through 94, 89, 90, 91, 93, i to thepositive pole andthis circuit remains closed until the identifying relay '92 opens itscontact. 91 which it will do when'the wipers 92, 93, 94 and 95 reach theset of bank contacts that belong to the calling subscriberwhohasappropriated the switch CS'for his call. iVhen this set of bankcontacts is reached an identifying circuit is closed which extends fromthe negative pole through 78 of the identifier DS, 8i, relay 82, wiper14E, wire96,iwire contact '91. The identifying relay also closes itscontact-s 101,102 whereupon a "current flows through the relay 3 in acircuit which extends from the negative pole'through the left winding of3,-wire 1, 101, 92, b, S, a, 93, 102 right winding of 3 to the positivepole. When the relay 3 energizcsit'opens the contact 98 and closes atits contact 103 a new energizing circuit for the relay 92- which extendsfroin the negative pole through 103 upper winding of identifying relay92, wire 10%, wiper 9 wire 31, contact-9, cut-cit relay 6 to thepositive pole. Thus, the energization of the relay 92 is now made todepend on the relay 3. Before the contact 98 is opened anew circuitestablished for the relay 82 through the contact 108 this circuitextending from the positive pole through 108, 97, 96, 14;, 82, 8 1, 7850 the negative pole. When the relay 3 opens the contact 52itestablishes'a new ircuit for the relays 43 and 51 which extendsthrough, the contact 109 and contact 110 to the positive pole. Thecircuit oft-he relays 51 and 43- is thus now made'to depend onthetestrelay tr.

It was shown in the foregoing description that the tens diallingimpulses go through the slow acting relay 55. The impulses keep Wheh allthe tens dialling impulses have been sent in, a. short pause ensuesduring which the relay allows its armatures to drop back. l l hen thecalling subscr1loer thereatter sends in the next series of diallingviinpuls 1 this next series flow from the posi tive pole through 22, 39,53, 122, slow-acting relay 123, contact 124, operating magnet 121 to thenegative pole. By this means the wiper 125 is set on to the proper unitsdesignating contact, say 126 for designating the particular set of bankcontacts wanted in the group of bank contacts that has already beendesignated in the switch lVS. When the units dialling impulses commenceflowing through the relay 123 this relay energizes and closes anenergizing circuit for the relay 128 which extends from the negativepole through 127, 128 to the positive pole. The relay 128 closes itscontacts 129, 130, 131, 132. By its contact 129 the relay 128 preoaresan oaeratin circuit for the drivin 22 m magnet 68 of the switch lVS.This circuit is closed when the units dialling impulses cease and therelay 123, is deenergized. This circuit extends from the negative polethrough the wiper 131 01": the. wanted line identifier DS which isoperated as will be described presently, bank contact 132, contact 130of the relay 123, contact 129 of relay 128 (which will have closed alocking circuit for itself extending from the positive pole through 130,136, 137, 40 to the negative pole), 140, wiper 48, corresponding bankcontact of the trunk finder TF, wire 141, contact 142 of the identifyingrelay 143, driving magnet 63, interrupter 2' to the positive pole of thebattery. The driving magnet 68 now drives the wipers 69, 70, 71, 72, 73forward until the wiper 70 reaches the bank contact 145 designated bythe wiper 125 having been set onto the bank contact 126 of the'unitsdesignating switch S, An identifying cur rent will. then flow from thenegative pole through 131 132, relay 146, wiper 125, contact 126, bankcontact 145, wiper 70, right winding of identifying relay 143, wire 148,

, corresponding bank contact of trunk finder Th, wiper 47, wire 149,bank contact 150, wiper 151 of the wanted line identifier DS' to thepositive pole. The identifying relay 143 and the relay 146 are thusenergized, the

:lormer relay opening the circuit of the driving magnet 68 at itscontact- 142, closing a locking circuit for itself which first extendsthrough the contacts 152 and 155 and then through a path leading throughthe contacts 153, 299 and 103. By means of contact 155' the identifyingrelay 143 applies the negative pole through 153, 155 to the test relaytr and, if the wanted subscriber is free, the test relay tr will now beenergized by a current flowing from the negative pole through 153, 155,tr, 160, wiper 71, test wire or wanted line corresponding to 161, acontact corresponding to 10, associated with the wanted line, cut-oflrelay associated with the wanted line and corresponding to 6, to thepositive pole of the battery. The test re-, lay tr on energizing opensat its contact-110 the circuit of the relays 51 and 43 which will haveextended at this time from the positive P0116 through 110, 109, 51, 50,45, 43, 201, 199 to the negative pole, and upon. the armature of therelay 43 dropping back impulses will flow from the positive pole throughthe interrupter 2', contact 41, 200, oil-normal contact 191, drivingmagnet 121 to the negative pole. The driving-magnet 121 will nowcontinue receiving impulses until it has driven its wiper 125 into thenormal position when the oil-normal contact 191 will be opened to stopthe operation of the magnet 121. When the relay 43 is deenergized asdescribed acurrent impulse also flows from the positive pole to theinterrupter 71, contact 41, 200, 198, relay 1.97, to the negative'pole.The relay 197 is'thus energized to close the circuit of the operatingmagnet 194 of the trunk finder TF, this circuit extending from thepositive pole through 2', 193, 194 to the negative pole. Whenever" animpulse flows through the magnet 194 an impulse will also flow through2', contacts 195, 196, upper winding of relay 197 to the negative pole,so that during the transition or stepping of the wipers of the trunkfinder TF from one set of bank contacts to the next the relay 197 willbe kept energized by an impulse through i. VVh'en this impulse through2' ceases the upper winding of the relay 197 will, whenever the wipersstrike a set of bank contacts belonging to an engaged or seized trunk,receive current through a contact 250 or 185, wire 251, wiper 49,contact 196 or through a contact corresponding to 192 in another trunkfinder and through the relay 197. When the wipers-oi? the trunk finderTF strike a. of contacts that correspond to a tree trunk that has notbeen seized by another trunk finder similar to TF the relay 197 will bedeenergized to open the circuit of the driving magnet 194. The momentthe wipers of the trunk finder TF are moved away from the set of bankcontacts leading to the trunk that was appropriated for the particularcall in question the locking circuit of the relay 82 which ex tendedfrom the a negative polev through 37,

82, 4A, 96, 97,108, to the positive pole was opened When the relay 82was energized in the manner hereinbefore described and opened itscontact 81 it caused the-deenergie zation of the, relay 79 and thus madethe ealling-lineidentifier DS available-for the other calls. 7 e

Thewanted line identifier DS had its Wipers 151, 270, 131 set; ontothe,bankcontacts corresponding to the units designating switch S in. thefollowing manner :-When the. relay 128 was energizediit. closed at itscontact 131 an operating circuit extending {110111 the positive polethrouglri,p131,:281, 282, 280,'to

the negative pole. At the same time the relay 128 applied the positivepoletothebank contact 283 so that when the -driving;magnet 280,- haddriventhe wipers 151, 270, 131 ontoathe set of bank-contactscorresponding to S a stoppingcircuit was, closed which extended from thenegative" pole through the relay 2,85, wiper270, contact 283, contact132=to the positive pole. The circuit through the relay 285 isopenedand-the wanted line identifier DS is made available for-1 othercalls :at the moment when the identifying circuit through the a relay,'1- l6=is CIOSBdyt'O open=ats contact 136 the locking circui-t-oftherelay 128 -w-l'iich-ex-tends from the positive pole through the lowerWinding of 128, contact 130, contact 136, wire 137 and; through thecontact 401.01% through the contact 201 199'to the negative pole. It ais thus seen that theWanted-line-identifier DS is madeavailabletor-another call as soon as the talking connection switchWS-with which it was coupled through 'IF has been set onto the bankcontacts leading to the line of,

the wanted subscriber.

The transitorily usedfinder F is made available for a new callvat themoment when the relay 197 is energizedinthemanner described above, whenthe contact :36iof the relay '197 is opened and the circuit fromthepositive'pole of the battery throu'gln21, r, 36

to the negativev pole is interrupted The relay'r is thendeenerg zed andcloses 'a-t-1tscontact the circuit leadingthrou'gh the conetact 20 ofthe slow acting relay 33, winding,

of the relay 301tothenegative polel The a relay 30 is thenenergizedianjdvopens (the cons tact -19 to interrupt-the circuityof therelayl;

24. When the relay 241 is deenergized the impulse relay 35 is 1disconneeted {from-the; calling line atthe contacts117and 18: The

driving magnet 25,- will, now; be reconnected through 13 to theswire'23which 1 leads to the! contacts, corresponding to 11] of itllvthfi linerelays of thisparticular group; ofgsubs'eribw ers. i

The events involvedin establishing a connection through the switchCS',':the;tr-unk T. and the w'anted lineselector WS were explained-aboveuptothepoint where thev -test relay tr had attracted its armature andopened also openedat103.

, the -.c ir cu-i t of. the relays 51 and l3uat its contactl l-O. Atitscontact16 1 the relay. tr closes tl1G-IG1TCL11lAOiE the ringing relay171, whichex tends fromthe negative pole through 280, 1641,

ringingrelay; 171, interrupter fito the pos-i tive pole." Ring ngcurrentis now 1nt6111'l1ttentlyr sentil'roin a ringing generator 291 through174, 180, 7 3 tovthe called subscribers stationandback through the.Wiper 72, contact 17 8, contact 175 back to the generator 291.; lVhentheWanted subscriber responds there;

lay 170 is energized and; at its contact 290 it opensithe circuit of theringing relay 171.

The calling subscriber S is now vconnected through tliewipers92, 93,contacts 101, 102, condensers,- contacts 172, 173, contacts 180, 178,Wipers 72, 73eto the line of the wanted subscriber.and-itheiconversation can proceed.

It the wanted subscriber should be engaged when the wipers olitheswitchWS'are set onto the wanted linethe test relay t1 will not beenbusy tone produced by the busytoneapparatus 182,183will be sentthrough the contacts 181,177, contact 172,173,,contac'ts 101,

, ergized as; as previouslydescribed and, the

lay 1 13. If the relay 82,-shouldnot have been I deenergiz edby the;displacement of; the wipers of the trunk finder TF as previously ex:plained itscircuit also will be openedgat. the contact 108- when therelay 3 is deenergized.

The holding circuit-ofthe test; relay tr which extends through 103, andthe contact 299 is I Should I the; calling subscriber abandon acallwhilewipers of the transitorily used switehiF are stil l set; on hisline the impulse relay-35 willrbe deenergizedtoopen the circuit of: therelay, 0" The contact 3 1; which is thenclosed closes the circuit of'therelay 30 i to open the Contact 19 and deenergize the re lay 2 1 and,ifthe units designating switch Si should have been-displacedibynumerical i n pulses this switch S willalso be restored t-o norxnalby,impulses that flow from the posi 1311 85 pole through 2', 11, 200,191,driving mag-j net121tothe negative pole. When therelay I I 51;.isdeenergizedon-the energization of the- 'testrelay tr-the aun iliaryswitch Sg'ot' the linain switch sVVS is in'nnediately restored by aimpulses that flow .from the' negative pole through the magnet of Sg,wiper 59, contact strip 300, contact 190, interrupteri -to the 7,

positive pole; While the auxiliary switch S9 e is being restored the.circuit of theydriving magnet'68is kept open at thepoint 299; by acontaet controlled by the test relay in Y It willrbe obvious thatinstead'of providing g a small. number ofisecondary' designatingswitches or units deslgnatlng switches 'S" which are common to a groupof main switches WS a secondary designating switch S may be provided foreach main switch. The number of secondary designating switches S willthen begreater but the circuit arrangement will thenbe simpler.

It may also be mentioned that the release of the main switch -WS which,as shown in Fig. 1, depends on the deenergization of the a release relaytr, which in turn is eiIected by the deenergization of the relay 3, maybe made to depend on the replacement of the called subscribe-rs receiverby means of an auxiliary release relay (not shown) that is operated whenthe relay 170 is energized and that then prepares a release circuit forWS f and comprising the stepping magnets 317,

334 are associated with the 322 and 333, trunk finder TF. 330 is theimpulse relay that receives the dialling impulses from the calling line.When a calling line has been connected through to the wanted lineselector and sends in the tens dialling impulses these impulses flowfrom the minus pole through the contact of the release relay 328,contact 332, 323, stepping magnet 322 (which steps the brushes 319, 326onto a certain contact, say the third contact 342) to the positive pole.The relay 381 closes the contact 308 and the wanted line connector IVSis then started by a current impulse from the minus pole through 313,operating magnets 312, 308, 310.

to the positive pole. The connector WS now shifts its wipers 310, 311causing the wiper 310 to contact with the contact strip 65. When thewiper 310 leaves the initial contact the relay 381 is deenergized, butimpulses continue flowing through 313, 312, 307, 65,

310 to the positive pole. The wipers 310, 311 are thus kept moving-andwhenever thewiper 310 encounters a new strip 65', 66, 67 an i impulse issent from the positive pole through 310, 305, 300 (operating magnet 317)to the negative pole. Theimagnet 317 moves the wiper 318 until itreaches the contact 341 corresponding to the contact 342 onto which thewiper 319 has been set by the tens impulses. The relay 304 is thenenergized by a current from the positive pole through 310, 304, 316,301, 318, 341, 342, 319, minus pole. The magnet 317 then has its circuitopened at and at the same time the positive pole is connected through310, 306, to the Wiper 311. Each time the wiper 311 encounters a newunits contact animpul se is sent through 310,306, 311, e14, e02, 337,33a to the minus pole. In the meantime the units connecting impulseswill havecome in and caused the operating magnet 334 to step the wiper336 onto a certain contact, say 340. When the wiper 335 reaches thecontact 339 corresponding to 340 an impulse will fiow through 310, 306,381, 303, 338, 339, 340, 336 to the negative pole and the relay 381 willthen open the circuit of 312 and stop the wipers IVS on the particularline that has been marked by means of the wipers 336 and 319. Iclairni 7f 1. In a telephone'system; lines impulse transmitters associated withsaid lines; a conversational switch with fixed contacts connected tosaid lines, movable contacts, and operating means for operating saidmovable contacts; an impulse receiving designating switch adapted to beset by a said impulse transmitter; starting means for starting saidoperating means immediately impulses commence being sent into theimpulse receiving switch from a said impulse transmitter; and means forcontrolling the operation of said movable contacts in accordance withthe setting ofthe impulse receiving designating switch.

2. In a telephone system; lines; impulse transmitters associated withsaid lines; a conversational switch with fixed contacts connected tosaid lines; other fixed designating contacts, movable contactscooperating with said designating contacts, and operating means foroperating said movable contacts; an impulse receiving designating switchwith contacts connected to said designating contacts and adapted to beset by a said impulse transmitter; starting means for starting saidoperating means immediately impulses commence being sent into theimpulse receiving switch from a said impulse transmitter; and means forcontrolling the operation of said movable contacts in accordance withthe setting of the impulse receiving designating .contacts connected tosaid designating contacts and adapted to be set by a said impulsetransmitter; starting means for starting said operating meansimmedlately lmpulses commence being sent into the impulse receiving swtch from a said impulse transmitter; and

means for controlling the operation of said movable contact inaccordance with the setting of the designating switch. f a

4. In a telephone system; lines; impulse transmitters associatedwith'said lines; a

conversational switch with groups of sets of fixed contacts connected tosaid lines, a fixed group designatmg contact allotted to each saidgroup, a movable-contact adapted to cooperate with the group designatingcon 7 tacts and moving means for moving the 'movable contact over thegroup designatmg contacts, an impulse receiving designating switch withbank contacts connected to said designating contacts, a movable Contactadapted to cooperate with the bank contacts, and means for setting themovable contact on a desired bank contact in response'to impulses froman impulse transmitter; start ing means for starting the operation ofsaid moving means immediately impulses from a said impulsetransmittercommence affecting the designating switch; and means forcontrolling the operation of the" movable contact of the conversationalswitch in accordance with the setting of the movable contact thatcooperates with said. bank contacts.

5. In a telephone system; lines; impulse transmitters associated withsaid lines; a rotary step-by-step conversationalsW-itch provided withgroups of sets of fixed contacts operation of said stepping magnet assoon as impulses from a said impulse transmitter commence affecting thedesignating switch; and means for controlling the operation of therotatable contact of the conversational switch in accordance with thesetting of said rotatablebrush.

6. In a telephone system; lines; impulse transmitters associated withsaidglin'es; a

rotary step-by-step conversational switch provided with groups of setsof fixed con tacts connected to said lines,a fixed group designatingcontact allotted to each said group, a contact-set designatingcontacttored to cooperate withthe group designating contacts, a second rotatablecontact adapted to cooperate with the contact-set designating contacts,and a driving magnet for driving the rotatable contacts; a primaryimpulse receiving group-designating switch provided with bank contactsconnected to said group designating contacts; a rotatable brush adaptedto cooperate with bank contacts and a brush-moving magnet for settingthe brush in response to impulses "from an impulse transmitter; startingmeans for starting the operation of said driving'magnet as soonas thetransmission or" ii'npu-lses from said line to a conversational switchcommences; means for controlling the operation of the rotatable contactot the con-- versational switch in accorda ce witht-he setti'ngoi saidrota't-ablebrush; and a secoinla designating switch for controlling themotion of said impt'ilse receiving contact-set second rotatable'contact.

7. In a telephone system; l1nes;'1n1pulse transmitters associated withsaid lines; a r0- tary step-by-step conversational switch provided withgroups of sets of lined con-tacts connected to said lines, a fixed groupdesig halting contact allotted to each said group; a contact-setdesignating contact for each contact set, a rotatable contact adapted tocooperate with the group designating contacts, a second rotatablecontact adapted to cooperate with the'contact-set designating contacts,and a driving magnet for driving the rotatable contacts; a primaryimpulse receiv ing group designating' switch provided with bankcontactsconnected tosaid group dcsig' nating contacts, a rotatable brushafd a 'ited to cooperate with bankcontacts and a brushmoving magnet forsetting thebrush in re'-' sponse to impulses from an impulsetransmitter; starting means for'starting the operation of said drivingmagnet ass con as the transmission o'fimpulses from a said line to i aconversational switch commences; means for controlling the operation ofthe rotatable contact of the conversational switch in accordance'withthe setting of said rotatable brush; i and a secondary impulse-receivingcontact-set designating switch comprising individual bank contactsconnected to said contact-set designating contacts,a wiper adapted tocooperate with said individual bank contacts, and a wiper-moving magnetton setting'the wiper; and means for controlling versational switchcomprising fixed contacts 1 connected to said lines and divided intogroups and members for selecting contact groups, an impulsereceiving-group desi each contact set, a rotatable contact adapt-natingdevice for controlling the selecting operation of said 'members inaccordance starting the operationof said "members as soon as impulsescommence being sent from a f said transmitter.

9. In a telephone system; lines; impulse conversational switchcomprising fixed con tact sets connected to said lines and dividedreceived; a'secondary impulse-receiving-contact-set designating device.for controlling the selecting operation oi a said member to select an.individual contact-set in accordance with impulses received; and meansfor starting the operation of the conversational switch as soon asimpulsesitor controlling it commence being receiv d.

10. In a telephone system; lines; impulse transmitters associated withsaid lines; conversational switches each comprising fined contact setsconnected to said lines and divided into groups and members forselecting a group of contact sets and any individual set in a group; aprimary impulse-receiving group designating device allotted to eachconversational switch for controlling the selecting operation of a saidmember to select a said group in accordance with impulses received;secondary impulse-receiving contact-set designating devices common to agroup of conversational switches for controlling the selecting operationof a sa d member to select an individual contact-set in accordance withimpulses received; and means for starting the operation of theconversational switch as soon. as impulses for controlling it commencebeing received.

11. In a telephone system; lines; impulse transmitters associated withsaid lines; conversational switches each comprising fixed contact setsconnected to said lines and dinating device with any conversationalswitch;

12. In a telephone system; lines; impulse transmitters associated withsaid lines; conversational switches; group designating means associatedwith each switch "for controlling it to select a group of lines inaccord ance with impulses sent from a said transmitter; and a devicecommon to a plurality of conversational switches for controlling anyswitch to select any individual line in agroup in accordance withimpulses sent from a transmitter and means for starting the operationor" a conversational switch immediately upon the receipt of numericalimpulses by a group designating means.

13. In a telephone system; lines; impulse transmitters associated withsaid lines conversational switches; group designating means associatedwith each switch for controlling it to select a group of lines in accorrance with impulses sent from a said transmitter; and means for startingthe operation of a conversational switch as soon as impulses forcontrolling it commence being received by a group designating means.

14:. lna telephone system; lines; impulse transmitters associated withsaid lines; conversational switches; group designating means forcontrolling a conversational switch to select a group of lines inaccordance with impulses sent from a transmitter; and means for startingthe operation of a conversational switch as soon as impulses forcontrolling it commence being received byra group designating means. e

15. In a telephone system; lines; impulse transn'iitters associated withsaid lines; conversational switches for selecting groups of said linesand provided with a selecting incinher that is movedto select a saidgroup only when the second or a higher group oflines is to be selected;and impulse-receiving group designating means for controlling theconversational switches to select a group of lines in accordance withimpulses received; and a starting means for starting the operation of aconversational switch as soon as a group designating meanscommencesreceiving impulsesfrom a said impulse transmitter.

16. In a'telephone system a calling line called lines register mechanismcomprising a step-by-step switch for registering thenumerical'ldesignation ot a called line, a con-' nector switchhavingcontacts in which the called line terminates, said contacts beingarranged in groups with a group designating contact for each group meansresponsive to the setting of said register for electrically marking thegroup designating contact of the called line and for also electricallymark ing the particular called line individually'in the group andmeansfor causing the brushes of said connector to first hunt for the markedgroup contact and then ffOltllGD'lfiIliGClllIlG contact. I

In testimony whereof I have afiixed my signature.

: FRITZ ALDE'NDORFF.

